Vault Raider

To unlock the secret door in Tulum you must solve all 16 Mayan Stelae puzzles. The first puzzle is part of DNA Sequence 4, Memory 1 and cannot be missed. After finishing this memory, the other stelae will become available. Some of them are on islands of dangerous ocean zones, so you should get your ship upgraded and continue with the story to make all locations accessible.You can also see the stelae locations on your map if you synchronize the viewpoints of their respective area. To check out which ones you have found, open up the progress tracker and select the "Mayan Stelae" tab. It provides an overview of islands that contain these secret puzzles.

Once all 16 puzzles have been solved, you need to travel to Tulum. There will be a marker on your map, saying "Mayan Outfit". Go there and open up the door to unlock the Vault Raider trophy / achievement, along with this new and unique outfit. The Mayan outfit deflects bullets from enemies shooting at you!